Film gate



M, G. CLAY Oct. 15, 1935.

2 Sheets-Sheet, 1

ATTORNEY Y R m OC T N 6 E VM mm U M BY we ,n Am.

Oct. 15, 1935. M. G, CLAY 2,017,203

FILM GATE Filed Sept. 5, 1951 2 Sheets-Sheet 2 INVENTOR MURRAY G. CLAY BY vm ATTORNEY Patented Oct. 15, 1935 UNITED STATES FILM GATE Murray G. Clay, New York, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application September 5, 1931, Serial No. 561,327

1 Claim.

This invention relates to fllm gates such are are used in motion picture apparatus and more particularly the variety thereof which are used in soundheads of combined motion picture machines and film sound reproducers, but it is to be understood that it is not limited to such sound gates asl the invention is likewise applicable to picture gates.

One object of the invention is to provide a simple, rugged, and inexpensive film gate.

Another object of the invention is to provide an improved lm gate which avoids the use of the usual pressure shoes which are forced against the film by compression, and substitute the use of shoes which are held against the iilm by longitudinal tension.

Another object of the invention is to provide improved means for readily adjusting the tension upon said shoes. Another object of the invention is to provide such a gate having shoes of such design that the pressure will be properly distributed over the area of the gate in order that the iilm may be drawn thereover Without any iiutter.

Another object of the invention is to provide improved means for independently adjusting the said pressure shoes.

Another object of the invention is to provide such a construction which permits the gate to be opened as far as possible within a relatively limited space to permit cleaning of the gate and easy insertion of the lm.

Another object of the invention is to provide such a gate wherein both the top and bottom of the gate open equal distances.

Another object of the invention is to provide such a gate including side guide mechanism and a bottom guide roller in the most compact location.

Another object of the invention is to provide such a gate wherein substantially all parts of the gate can be made by stamping.

Another object of the invention is to provide such a gate with a locking mechanism capable of easily operating and accurately locking the gate in closed position.

In the drawings:

Fig. l is a side view of the gate, open, looking toward the aperture plate from the operating side of the gate;

Fig. 2 is a view of the gate looking away from the aperture gate and toward the pressure shoes from underneath;

Fig. 3 is a view corresponding generally to Fig. 1 but showing the gate in closed position.

The gate consists of a base plate or equivalent member I which, of course, may be formed from one of the members of the machine to which the gate is attached. Upon this is mounted the aperture plate 2 which as shownis in the form of a 5 single stamping attached to the base member I and with the sides bent back to carry the bearing members for the side guides and rolls; the side guides being shown at 3 and the lower guide roll 10 at 4.

These two guide rolls, as will be apparent from the drawings, are conventional in design, but the aperture plate is curved convexly toward the film, and these members 3 and 4 are mounted on the concave side of the gate so as to take up the least 15 possible amount of room. 'I'he gate is, of course, provided with the usual apertures 5 and 6.

Movable toward and away from the aperture plate 2 is a frame member 1 which is likewise formed from a single stamping and is provided 20 with an appropriate aperture 8. This frame member carries the two tension shoes 9 which are adapted to cooperate with the central portion of the aperture plate. These tension shoes are held to the frame member by the screws IIJ and are 25 held to the adjusting blocks II by the screws I2. The adjusting blocks being movable by means of the screws I3 in order to vary the tension upon the shoes 9.

The screws I0 also hold the pressure shoes I4 30 which are made in the form of loops and serve to maintain the illm substantially in Contact with the aperture plate 2 where it passes between the guide rolls 3. This pair of shoes I4 is provided" with-a slight clearanca-say about .002 inch,-in 35 order that ythey may not tend to cause any friction with or vibration of the illm.

The frame member 'I is supported by and j moved toward and away from the aperture plate 40 2 by a parallel link mechanism.

'Ihis mechanism consists of two links I5 and I6. It will be noted that the length of link I5 is very slightly greater than that of the link I6 in order that the bottom of the pressure plate may be retracted as far as possible, since there is nothing 45 to interfere with at the bottom as there is at the top. The top link I6 is continued in the form of the arm I1 which constitutes an operating handle and this operating handle is provided with a knob I8 which is provided at the opposite side of the 50 arm I1 with a pin adapted to fall into the hole I9 in the member 2. A groove 20 is provided in the mmber 2 to guide this pin toward the hole without necessitating the lifting of the arm to permit closing of the gate. When the handle I8 is merely 55 pushed toward a. closed position, the pin referred to will slide upon the groove 20 and drop into the hole I9 thereby securely locking the gate in closed position.

I claim:

A lm gate comprising an aperture plate and a movable pressure plate, and unitary means constituting a supporting link mechanism, operating mechanism, and locking means for actuating said movable pressure plate.

MURRAY G. CLAY. 

